This invention is in the field of antennas, particularly vehicle antennas having multi-band capability. Motor vehicles have for many years been equipped with radio receivers for entertainment and information. The typical passenger automobile is equipped with a combined AM/FM radio for this purpose. These radios typically use a single whip antenna for receiving radio signals.
More recently there is much interest in high frequency mobile radio communication systems in motor vehicles. This interest particularly relates to mobile cellular telephones. Cellular telephone systems operate at much higher frequencies than the AM or even the FM broadcast bands. The AM broadcast band is roughly centered around 1 MHz and the FM broadcast band is roughly centered around 100 MHz. The cellular telephone system employs one band for transmission and a second nearby band for reception. These two bands are in the range between 800 and 900 MHz. Because of the difference in frequency between the cellular telephone band and the AM and FM bands, it is typical in the prior art to use a separate antenna for the mobile communications system.
There are problems with the use of a separate antenna. Modification of the vehicle is often required to accommodate the separate antenna. This often involves drilling holes for mounting the antenna and the like. The introduction of cellular telephone systems with separate antennas precipitated numerous instances of theft or vandalism of the mobile communications equipment. The separate antenna used by the mobile communications equipment system serves to alert potential thieves and vandals of the presence of the mobile communications equipment.
There have been attempts in the prior art to produce a single antenna which is capable of operating on the AM/FM bands and the higher frequency mobile communication bands without success. There is therefore a need in art for a single antenna which can operate on these bands and which is visually indistinguishable from the prior art AM/FM whip antenna.